1. Field of the Invention
The present invention relates to valve actuators, and more particularly to flux shifting valve actuators based upon stress sensitive amorphous magnetic material.
2. Background Art
In prior magnetic flux-shifting fluid valves, the shifting of a magnetic flux causes a movable valve element to reposition in order to control the flow of a fluid therethrough.
As disclosed in U.S. Pat. No. 4,072,918 to Read, Jr. an electromagnetic bistable actuator employs a first magnetic circuit adapted for maximizing flux flow through an armature and a second magnetic circuit adapted to maintain magnetization of a permanent magnet.
Yet another functional magnetic flux-shifting fluid valve is disclosed in U.S. Pat. No. 4,403,765 to Fisher. Fisher utilizes in part, two permanent magnets, one having a relatively high coercive force and the other having a relatively low coercive force. A change in the magnetization of the magnet having a relatively low coercive force results in the fluxes of the two magnets being either in series across a working air gap or in parallel through a diverting shunt path in order to operate the valve.